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Abstract:

The invention relates to manufacturing a surgical guide to be placed in a
patient's mouth. The patient's mouth is scanned to obtain surgical-region
scan data at a region where an implant is to be located. The patient's
mouth is also scanned in the opened position to acquire dental conditions
opposite from the surgical region so as to obtain opposing-condition scan
data. A virtual model is developed using the surgical-region scan data
and the opposing-condition scan data. Using the virtual model, a surgical
plan is developed that includes the location of the implant to be
installed in the patient. A virtual surgical guide is also developed
based on the surgical plan. The dimensions of instrumentation to be used
with the surgical guide are checked to ensure they will fit within the
mouth by use of the opposing-condition scan data. After checking, final
surgical-guide manufacturing information is obtained for manufacturing
the surgical guide.

Claims:

1-32. (canceled)

33. A method of developing a surgical plan for performing surgery in a
patient's mouth, the method including: receiving surgical-region data of
a surgical region and opposing-condition data including dental conditions
opposite the surgical region, to develop a virtual model of the patient's
mouth on a computer system, the virtual model being displayed on a
display; using the virtual model to determine an available dimension from
the surgical region to dental structures opposite the surgical region;
using the virtual model to check dimensions of instrumentation to be used
during the surgery to ensure that the instrumentation will fit within the
patient's mouth during the surgery; and in response to the checking of
the dimensions of the instrumentation indicating a workable condition,
finalizing the surgical plan developed from the virtual model, the
surgical plan including a surgical protocol of the instrumentation to be
used during the surgery.

34. The method of claim 33, further comprising, in response to the
checking of the dimensions of the instrumentation indicating an
unworkable condition, altering the instrumentation so that the altered
instrumentation has a dimension that is less than the available
dimension.

35. The method of claim 33, wherein the surgery includes placing at least
one dental implant in the patient's mouth.

36. The method of claim 35, wherein the surgical plan further includes a
location of the at least one dental implant.

37. The method of claim 35, further comprising developing a virtual
surgical guide to be placed in the patient's mouth, wherein, in response
to the checking of the dimensions of the instrumentation indicating an
unworkable condition, altering the virtual surgical guide.

38. The method of claim 37, further comprising manufacturing a surgical
guide to be placed in the patient's mouth based on the altered virtual
surgical guide.

39. The method of claim 35, wherein, in response to the checking of the
dimensions of the instrumentation indicating an unworkable condition,
altering the size of at least one dental implant.

40. The method of claim 33, further comprising displaying the
instrumentation within the virtual model on the display.

41. The method of claim 33, wherein one of the surgical-region data and
the opposing-condition data is obtained using a CT-scanner.

42. The method of claim 33, wherein the dental conditions opposite the
surgical region include natural teeth or gingival tissue.

43. A method of developing a surgical plan for performing surgery in a
patient's mouth, comprising: receiving (1) opposing-condition scan data
from a scan of the patient's mouth in an opened position, the
opposing-condition scan data including dental conditions opposite the
surgical region, and (2) bite registration data between upper jaw
conditions and lower jaw conditions to develop a virtual model of the
patient's mouth on a computer system; using the virtual model to
determine an available dimension from the surgical region to dental
structures opposite the surgical region; using the virtual model to check
dimensions of instrumentation to be used during the surgery to ensure
that the instrumentation will fit within the patient's mouth during the
surgery; and in response to the checking of the dimensions of the
instrumentation indicating a workable condition, finalizing the surgical
plan developed from the virtual model, the surgical plan including a
surgical protocol of the instrumentation to be used during the surgery.

44. The method of claim 43, further comprising, in response to the
checking of the dimensions of the instrumentation indicating an
unworkable condition, altering the instrumentation so that the altered
instrumentation has a dimension that is less than the available
dimension.

45. The method of claim 43, wherein the surgery includes placing at least
one dental implant in the patient's mouth.

46. The method of claim 45, wherein the surgical plan further includes a
location of the at least one dental implant.

47. The method of claim 45, further comprising developing a virtual
surgical guide to be placed in the patient's mouth, wherein, in response
to the checking of the dimensions of the instrumentation indicating an
unworkable condition, altering the virtual surgical guide.

48. The method of claim 47, further comprising manufacturing a surgical
guide to be placed in the patient's mouth based on the altered virtual
surgical guide.

49. The method of claim 45, wherein, in response to the checking of the
dimensions of the instrumentation indicating an unworkable condition,
altering the size of at least one dental implant.

50. The method of claim 43, further comprising displaying the
instrumentation within the virtual model on the display.

51. The method of claim 43, wherein one of the surgical-region data and
the opposing-condition data is obtained using a CT-scanner.

52. The method of claim 43, wherein the dental conditions opposite the
surgical region include natural teeth or gingival tissue.

53. The method of claim 43, wherein the bite registration data is
obtained from a CT-scan of a scanning appliance having impression
material thereon, the impression material including the patient's bite
registration.

54. A method of pre-operative visualization in a patient's mouth,
comprising: receiving scan data of a patient's mouth in an opened
position to acquire dental conditions opposite a surgical region so as to
obtain opposing-condition scan data; and using a virtual model of the
surgical region of the patient's mouth and the opposing-condition scan
data to determine whether instrumentation to be used during surgery will
fit within the patient's mouth, the virtual model being displayed on a
display.

Description:

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent application Ser.
No. 13/526,717 filed Jun. 19, 2012, which is a continuation of U.S.
patent application Ser. No. 13/179,609, filed Jul. 11, 2011, which is a
continuation of U.S. patent application Ser. No. 12/425,202, filed Apr.
16, 2009, which claims the benefit of U.S. Provisional Application No.
61/124,331 filed Apr. 16, 2008, both of which are hereby incorporated by
reference in their entireties.

FIELD OF INVENTION

[0002] The present invention relates generally to use of CAD-CAM
methodologies for installing dental implants. More particularly, the
present invention relates to a method for pre-operative visualization of
the location and positions of instrumentation that will be used with a
surgical guide in placing a dental implant.

BACKGROUND OF THE INVENTION

[0003] The dental restoration of a partially or wholly edentulous patient
with artificial dentition is typically done in two stages. In the first
stage, an incision is made through the gingiva to expose the underlying
bone. After a series of drill bits creates an osteotomy in the bone, a
dental implant is placed in the jawbone for integration. The dental
implant generally includes a threaded bore to receive a retaining screw
holding mating components therein. During the first stage, the gum tissue
overlying the implant is sutured and heals as the osseointegration
process continues.

[0004] Once the osseointegration process is complete, the second stage is
initiated. Here, the gum tissue is re-opened to expose the end of the
dental implant. A healing component or healing abutment is fastened to
the exposed end of the dental implant to allow the gum tissue to heal
there around. Preferably, the gum tissue heals such that the aperture
that remains generally approximates the size and contour of the aperture
that existed around the natural tooth that is being replaced. To
accomplish this, the healing abutment attached to the exposed end of the
dental implant has the same general contour as the gingival portion of
the natural tooth being replaced.

[0005] During the typical second stage of dental restoration, the healing
abutment is removed and an impression coping is fitted onto the exposed
end of the implant. This allows an impression of the specific region of
the patient's mouth to be taken so that an artificial tooth is accurately
constructed. After these processes, a dental laboratory creates a
prosthesis to be permanently secured to the dental implant from the
impression that was made.

[0006] In addition to the more traditional system for placing dental
implants described above, some systems use guided placement of the dental
implants. In these situations, a surgical plan is developed for the
patient that will include the location and orientation of the implants to
be installed by a surgical guide. Once the surgical plan is known, the
surgical guide can be developed and, eventually, placed in the patient's
mouth at the known location. The surgical guide includes openings for
providing the exact placement of the drill bits used to create the
osteotomy. Once the osteotomy is completed, the surgical guide may permit
the dental implant to be placed through the same opening and enter the
osteotomy that was guided by the surgical guide.

[0007] Surgical guides can be created by the use of a CT-scan of the
patient's mouth. The CT-scan provides enough detail to develop the
surgical guide by use of various methods. For example, a CT-scan can
provide the details of the patient's gum tissue and/or remaining teeth so
that the surgical guide can be developed based on computer-aided design
(CAD) and computer-aided manufacturing (CAM). One example of the use of a
CT-scan is disclosed in

[0008] U.S. Patent Publication No. 2006/0093988, which is herein
incorporated by reference in its entirety. This publication also
describes the use of various tubes that can be placed within the surgical
guide to receive the drill bits and implants.

[0009] However, some problems may occur with the development and
manufacturing of the surgical guide. For example, the surgical plan may
require the use of a certain sized implant, dental drill, or other
components that may not fit well in the patient's mouth due to the
opposing (i.e., upper or lower) teeth and/or gum tissue in the patient's
mouth. Thus, the clinician may be disappointed because of the
considerable amount of time and effort in planning the case, only to need
a revised plan and possibly a new surgical guide. The patient, of course,
is also disappointed because he or she did not receive what was expected
in that visit (possibly a temporary prosthesis) and will be forced to
return an additional day to complete the project.

[0010] As such, a need exists to develop an improved CAD-CAM related
methodology for developing a surgical plan and a surgical guide that is
used in accordance with the surgical plan.

SUMMARY OF THE INVENTION

[0011] In one aspect, the present invention is a method of manufacturing a
surgical guide to be placed in a patient's mouth, comprising scanning a
patient's mouth to obtain surgical-region scan data in a surgical region
at which at least one dental implant is to be located, scanning a
patient's mouth in the opened position to acquire dental conditions
opposite from the surgical region so as to obtain opposing-condition scan
data, and developing a virtual model of the patient's mouth using the
surgical-region scan data and the opposing-condition scan data. The
method further includes developing, with the use of the virtual model, a
surgical plan that includes the location of the at least one dental
implant to be placed in the mouth of the patient, developing a virtual
surgical guide based on the location of the at least one dental implant
and the surgical-region scan data, and checking the dimensions of
instrumentation to be used with the surgical guide to ensure the
instrumentation will fit within the patient's mouth by use of the
opposing-condition scan data. After the checking step, the method
includes obtaining final surgical-guide manufacturing information based
on the virtual model, and manufacturing the surgical guide based on the
final surgical-model manufacturing information.

[0012] In another aspect, a method of manufacturing a surgical guide to be
placed in a patient's mouth, comprises developing a virtual model of the
patient's mouth using scan data from the patient's mouth, and developing,
with the use of the virtual model, a surgical plan that includes the
location of multiple dental implants to be placed in the mouth of the
patient. The surgical plan includes a surgical protocol of
instrumentation to be used to install the multiple dental implants. The
method further includes developing a virtual surgical guide based on the
surgical plan and, by use of opened-mouth scan data from an opened-mouth
condition from the patient's mouth, determining an available dimension
from the virtual surgical guide to dental structures that are opposing
each of the multiple dental implants. In response to the available
dimensions being less than a dimension for the instrumentation to be used
with each of the multiple dental implants, the method includes altering
the surgical plan, obtaining final surgical-guide manufacturing
information based on the virtual model after the altering, and
manufacturing the surgical guide based on the final surgical-model
manufacturing information.

[0013] According to a further aspect of the invention, a method of
developing a surgical guide to be placed in a patient's mouth comprises
developing, with the use of a virtual model from the patient's mouth, a
surgical plan that includes the location of multiple dental implants to
be placed in the mouth of the patient. The surgical plan includes a
surgical protocol of instrumentation to be used to install the multiple
dental implants. The method further includes developing a virtual
surgical guide based on the surgical plan, and by use of opened-mouth
scan data from an opened-mouth condition from the patient's mouth,
determining an available dimension from the virtual surgical guide to
dental structures that are opposing each of the multiple dental implants.
Further, the method includes comparing the available dimensions to
dimensions for the instrumentation, and altering at least one of (i) the
instrumentation, (ii) the virtual surgical guide, (iii) the implant size,
and/or (iv) the implant location in response to the dimensions for the
instrumentation being greater than the available dimensions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a side view of a scan of a patient's mouth with the mouth
closed;

[0015]FIG. 2 is a front view of a scan of the patient's mouth with the
mouth opened;

[0016]FIG. 3 illustrates a virtual image of the patient's mouth, and a
surgical guide to be used in accordance to a surgical plan;

[0017] FIG. 4 is an illustration of a side view of a surgical drill that
is to be used in accordance with the surgical plan;

[0018]FIG. 5 is an illustration of a side view of a dental implant and a
dental implant mount that are to be used in accordance with the surgical
plan;

[0019]FIG. 6 illustrates a virtual image of the patient's mouth using the
surgical plan, with the dental implant of FIG. 5 and the surgical drill
of FIG. 4 being displayed relative to the surgical guide;

[0020]FIG. 7 illustrates the actual surgical guide of FIGS. 3 and 6 after
it has been manufactured;

[0021] FIG. 8 illustrates a kit containing various components that are
used with the surgical guide to create an osteotomy in the patient's
mouth and to install a dental implant;

[0022] FIG. 9 illustrates the surgical guide of FIG. 7 after it has been
placed in the patient's mouth, along with a drill bit that is used to
develop an osteotomy;

[0023] FIG. 10 illustrates the surgical guide of FIG. 7 after it has been
placed in the patient's mouth, along with a dental implant that is being
installed in the osteotomy; and

[0024]FIG. 11 illustrates a flow chart of the process used to develop the
surgical plan and the surgical guide.

[0025] While the invention is susceptible to various modifications and
alternative forms, specific embodiments thereof have been shown by way of
example in the drawings and will herein be described in detail. It should
be understood, however, that it is not intended to limit the invention to
the particular forms disclosed but, on the contrary, the intention is to
cover all modifications, equivalents, and alternatives falling within the
spirit and scope of the invention as defined by the appended claims.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0026]FIG. 1 illustrates a first scan 10 of a patient's mouth with the
mouth in a closed position. In this example, the patient is in need of
multiple dental implants in the lower jawbone. Multiple scans may be
taken from the sides to obtain scan data reflecting the entire condition
of the lower jawbone. The scanning of the patient's mouth may be achieved
by a CT scanner (or other scanning technologies or devices) to obtain
scan data regarding the details of the bone structure, teeth and
overlying gingival tissue. The first scan 10 usually involves a scanning
appliance that is placed in a patient's mouth. As is known in the art, a
scanning appliance is used for a partial or fully edentulous patient and
includes physical shape information representing the desired prosthetic
teeth in the region, usually with added material (e.g., barium sulfate)
that can be picked-up by a typical CT scan.

[0027] The first scan 10 of the patient's mouth is useful in developing a
surgical plan for the patient. When considering a dental surgical plan
for a specific patient, the location and orientation of the implants
relative to the surface of the gingival tissue, remaining teeth, and the
underlying bone is important. Additionally, the maximum depth of the
distal end of the implant within the bone is also important to the
surgical plan, so as to avoid the sinus cavity and mandibular canal. As
will be discussed in more detail below, the surgical plan will dictate
the development of the surgical guide that fits snugly onto the surface
of the tissue by having a negative impression that incorporates the
details of the tissue surface in the patient's mouth. By the term
"tissue" in the present specification, it is understood that tissue can
be hard tissue (such as bone tissue or teeth) and soft tissue (such as
the gingival tissue).

[0028]FIG. 2 illustrates a second scan 20 of the patient's mouth with the
mouth in the opened position. Bite blocks may be used to assist the
patient in holding his or her mouth in the opened position. If the
patient is wearing a removable denture in the jaw opposing the
implant-receiving region, then they would remove it during the second
scan 20. Like the first scan 10 of FIG. 1, the second scan 20 may be
achieved by a CT scanner that produces scan data that can be entered or
downloaded into a computer for developing the surgical plan. As will be
described in detail below, the second scan 20 allows the surgical plan to
take into account the spatial constraints within the mouth of that
particular patient. In other words, the scan second 20 provides
dimensional limitations to be measured between the opposing dental
structure (e.g., teeth and/or gingival tissue) and the surgical guide
that will be placed on the lower jawbone in this particular patient.

[0029]FIG. 3 illustrates a virtual model 30 of the patient's mouth that
has been derived from the scan data from FIG. 1 and the opened-mouth scan
data from FIG. 2. In particular, the virtual model 30 is shown on a
computer display 35 and includes the upper jaw (maxillary) 40 and the
lower jaw (mandible) 45. The relative dimensions between the upper jaw 40
and the lower jaw 45 are derived from the second scan 20 of the patient's
mouth in the opened position. Additionally, a virtual surgical guide 50
is located on the lower jaw 45 and includes virtual openings 52 that have
been established for receiving instrumentation, such as tissue punches,
drill bits, counter sinks, and the dental implant that is needed for
surgery. The surgical guide 50 is developed based on the desired
locations in the lower jaw 45 of the dental implants as determined by the
first scan 10 from the patient's mouth. Thus, prior to the display of the
virtual surgical guide 50, the technician working on this case for the
patient would have placed various sizes of virtual implants at ideal
locations and orientations in the lower jaw 45 for properly supporting a
prosthesis, such as a denture or a partial denture. The technician
chooses the sizes of the dental implants, as well as their locations and
angles, based on the various bone densities and underlying tissue (e.g.,
sinus cavity or mandibular canal) provided by the scans 10 and 20. One
example of the display of the virtual implants is shown in FIG. 6.

[0030] Based on the virtual model 30, the height dimension between the top
of the virtual surgical guide 50 and the opposing dental structures (in
this case, teeth) can be easily determined. As shown, the height
dimensions H1, H2, H3 and H4 are provided for four openings 52 in the
virtual surgical guide 50 and generally correspond to the maximum height
for instrumentation that will be permitted in the mouth of this
particular patient due to the second scan 20 from FIG. 2. These height
dimensions H1, H2, H3 and H4 are measured along the axis of the opening,
which is also coincident with the axis of the planned virtual implant for
that site. Thus, because the implants may not be installed in a parallel
fashion due to constraints such as adjacent teeth or inadequate bone
densities in certain regions of the patient's mouth, the direction of
measurement of the height dimensions H1, H2, H3 and H4 may not be
parallel either.

[0031] As an example, a virtual model 30 may include a hand depiction 60
of the clinician and, more importantly, a virtual drill bit 65 attached
to a virtual hand piece 67 that may be needed for drilling the osteotomy
for the implant to be inserted through the openings 52 corresponding to
height dimension H3. If the height dimension H3 is less than the length
of the instrumentation necessary to complete the implant installation on
the virtual model, then alterations must be made to be surgical plan so
that the instrumentation will fit within the patient's mouth at each
surgical location. Examples of such alterations may include (i) changes
to the size of the implant or the implant mount, (ii) changes to the
location (e.g., angular orientation and/or position) of the implant in
the bone, (iii) changes to the surgical guide, and/or (iv) changes to the
instrumentation that is to be used for a certain implant.

[0032] The surgical planning software may utilize different points of
reference other than the exterior surface of the virtual surgical guide
50 when comparing the dimensions. For example, the surgical planning
software may simply place the master tubes (see FIG. 7) within the
virtual model 30 and measure along the central axis from the top of the
master tubes. Alternatively, the surgical planning software may utilize
some rough estimation for height and thickness dimensions of certain
types of surgical guides and make the determination using the estimated
height and/or thickness of the surgical guide. While this latter option
does not present an exact calculation, the estimation may be enough to
ensure that the instrumentation will fit within the patient's mouth.

[0033] When determining whether the instrumentation will fit for each
implant, the software program may simply choose the required instrument
having the longest length (e.g., longest drill bit) or combination of
instruments having the longest total length (e.g., implant, implant
mount, surgical hand piece). If the instrument having the longest length
will fit into the patient's mouth for that particular implant site, then
all remaining instruments for that particular implant site should fit as
well. As used herein, it should be understood that "instrument" and
"instrumentation" can mean a single component (e.g. drill bit) or
multiple components that are coupled together (e.g., driver plus drill
bit, or implant, implant mount and surgical hand piece).

[0034] FIG. 4 illustrates the virtual drill bit 65 and the associated
power driven hand piece 67 along with their respective tool length
dimensions, T1 and T2. These dimensions, T1 and T2, are stored within
memory devices accessible by the software program that is used in
association with the virtual model 30. These dimensions T1 and T2 can be
compared against the maximum height dimensions (H1, H2, H3, H4) in the
virtual model 30 to ensure that the drill bit 65 can fit within the
patient's mouth during the actual surgery. Similar dimensions would also
be stored for other sizes of drill bits as well. Further, while FIG. 4
illustrates just one type of tool (e.g., a drill bit 65) dimensions of
the various types of tools (taps, countersinks, etc.) needed for surgery
would also be stored in the memory device associated with the software
program that is used to conduct the virtual modeling.

[0035]FIG. 5 illustrates a virtual dental implant 70 having an internal
anti-rotational feature 72. The virtual dental implant 70 is connected to
a virtual implant mount 80 with a screw such that the internal
anti-rotational feature 72 mates with a corresponding anti-rotational
feature 82 on the implant mount 80, just as occurs in an actual dental
implant. The implant mount 80 includes an upper flange 86 with slots 87
aligned with the anti-rotational feature 82 such that the orientation of
the anti-rotational feature 72 of the implant 70 can be visualized by an
inspection of the slots 87. The implant mount 80 includes an upper
driving portion 89 that attaches to a virtual power-driven dental device
90, such as a dental hand piece. For purposes of virtual modeling, these
details of the implant 70 and implant mount 80 are not necessary.
However, they have been included in FIG. 5 to provide insight as to the
construction of the implant 170 and implant mount 180 as discussed in
more detail below relative to FIGS. 8-10.

[0036]FIG. 5 generally illustrates the length of the combination of the
virtual implant mount 80 and the implant 70 as I1 and the length of the
virtual power-driven dental device 90 as I2. These dimensions, I1 and I2,
are stored within a memory device accessible by the computer program that
is used in association with the virtual model 30. Accordingly, these
dimensions I1 and I2 can be compared against the maximum height
dimensions (H1, H2, H3, H4) in the virtual model 30 to ensure that the
implant 70 and its associated implant mount 80 can fit within the
patient's mouth during the actual surgery. Preferably, images of the
implant 70, the implant mount 80, and the power driven dental device 90
are also stored in memory device so that virtual representation of the
components can be provided on the display 35 to the technician working on
the virtual model.

[0037] Because the surgical plan involves the placement of the implant 70
at a certain depth below the surgical guide, the implant mount 80 is
provided in various lengths. In actual surgery, the depth of penetration
of the combination of the implant and the implant mount is limited by the
surgical guide and, specifically, the master tubes surrounding the
openings in the surgical guide that engage the flange on the implant
mount, as is discussed below. Accordingly, as just one example of an
alteration of the surgical plan, if the combined height of the implant 70
and its associated implant mount 80 exceeds the maximum height dimension
(e.g., H3), the implant mount 80 may be selected to have a shorter length
such that the top of the implant 70 does not penetrate as deep into the
bone as would occur with the originally selected implant mount.

[0038]FIG. 6 illustrates an alternative display of the virtual model 30
of FIG. 3. FIG. 6 illustrates the virtual surgical guide 50 and eight
virtual implants 70a, 70b, 70c, 70d, 70e, 70f, 70g, 70h. The size and
locations of the virtual implants 70 are determined in accordance with
the surgical plan, as dictated by the first scan 10 of the patient's
lower jaw. Once the locations and sizes of the virtual implants 70 are
determined, the virtual surgical guide 50 is developed with an underside
surface that will fit over and mate with the patient's gingival tissue
and/or remaining teeth in the lower jaw bone. FIG. 6 also illustrates the
use of the drill bit 65 of FIG. 4 and the installation of a certain
dental implant 70b. As can be seen, the overall height dimensions of
these two instruments can be compared with the corresponding maximum
height dimensions (shown in FIG. 3 as H2 and H4) for virtual implant 70b
and 70h, respectively. Thus, it is not necessary to show the image of the
upper jaw bone 40 of FIG. 3 to make the necessary comparison of
dimensions.

[0039]FIG. 7 illustrates the actual surgical guide 110 that is
manufactured in accordance to standard CAD-CAM techniques based on the
virtual surgical guide 50. The surgical guide 110 can be produced from
various materials and techniques. One preferred method is using a
rapid-prototyping technique. Because there is a need for eight implants,
the surgical guide 110 includes eight openings, each of which is defined
by a master tube 120 that is integrated into the material of the surgical
guide 110 with the assistance of the outer roughened surface and
adhesive. The master tubes 120 are located on flat surfaces 122 that are
substantially flush with the top surface of the master tubes 120. The
master tubes 120 have notches 124 that can be aligned with the slots 87
on the flange 86 of the implant mount 80 to dictate the exact location of
the anti-rotational feature of the implant when installed in the
patient's mouth. The under portion of the surgical guide 110 (not visible
in FIG. 7) has a contour that follows the scan 10 (FIG. 1) of the
gingival surface and/or remaining teeth in the patient's lower jaw bone.
In other words, the under portion of the surgical guide 110 is a negative
impression of the patient's conditions in the lower jaw bone. The
surgical guide 110 also includes a plurality of openings 128 through
which temporary fixation screws or pins can be placed. The temporary
fixation screws or pins engage the bone and hold the surgical guide 110
in the proper location so that the surgical plan can be executed using
the surgical guide 110.

[0040] As can be seen, the actual surgical guide 110 and the image of
virtual surgical guide 50 on the display 30 may have a slightly different
appearance because the virtual surgical guide 50 was only for determining
the available dimensions. In other words, the virtual surgical guide 50
is more of a schematic illustration for purposes of determining the
available dimensions. Whereas the flat surfaces 122 on the actual
surgical guide 110 are variables chosen to accommodate the different
lengths of the implant amounts that are available for attachment to a
specific dental implant, the actual locations of the flat surfaces 122 on
the virtual model can be accounted for in the dimensional comparison.
Alternatively, the present invention contemplates the display of a
virtual surgical guide 50 on the display 30 that is identical to the
structure of the actual surgical guide 110.

[0041] Further, while the surgical guide 110 has been described relative
to the use of a surgical plan with eight dental implant, the present
invention is also useful for developing and installing single implants.
Thus, the surgical guide 110 may be smaller such that it only covers a
limited portion of the dental arch. The surgical guide 110 could be used
for installing implants that support a multi-tooth prosthetic device or a
full denture.

[0042] FIG. 8 illustrates a surgical kit 150 that contains the
instrumentation that may be used to conduct the surgery with the surgical
guide 110. It is these instruments that have dimensions (and preferably
images) that are stored within the memory devices used with the software
program for the virtual modeling. More details of the surgical kit 150
and the methods of using the surgical kit 150 in accordance with a
surgical plan are disclosed in U.S. Patent Application Ser. No.
61/003,407, filed Nov. 16, 2007, and described in Biomet 3i's
Navigator® system product literature, "Navigator® System For CT
Guided Surgery Manual" that is publicly available, both of which are
commonly owned and herein incorporated by reference in their entireties.

[0043] In FIG. 8, the lower portion of the surgical kit 150 includes the
bone profilers 160 for shaping the bone surface at the osteotomy. The
lower portion of the surgical kit 150 also includes implant mounts 180 of
various sizes. For example, for each of the 3 mm, 4 mm, and 5 mm
diameters of the implant mounts 180 for mating with correspondingly sized
implants, the available lengths are 7.5 mm, 9.0 mm, 10.5 mm, and 12.0 mm.
The surgical plan may require a set of implants having different lengths
and that are positioned at different depths in the bone. Thus, the
various lengths of the implant mounts 180 are needed to accommodate those
dimensional variables in accordance with the surgical plan.

[0044] The upper portion of the surgical kit 150 in FIG. 8 includes drill
bits 165, which may include taps for creating female threads within the
osteotomy. Each of the drill bits 165 is of a different size in the
length dimension (rows A, B, C, D, and E) and diametric dimension (e.g.,
2.0 mm, 2.75 mm, 3.0 mm, 3.25 mm, 3.85, mm, 4.25 mm). Each drill bit 165
has a stop flange that engages the top surface of guide tubes tools 190
(discussed below) that fit within master tube 120 of the surgical guide
110 (FIG. 7) to control its depth of insertion. Thus, when the surgical
plan is finally established (after comparison of the height dimensions
discussed with reference to FIGS. 3-6), a specific series of drill bits
165 is chosen to be sequentially used with the surgical guide 110. For
example, for a certain dental implant to be installed, the dental plan
may call for the drill bits of B-2.0 mm and B-3.25 mm. The dimensions of
the osteotomy are defined by the last drill bit (B-3.25 mm), which has a
drill bit length dimension that accommodates the installation of that
certain dental implant.

[0045] The surgical kit 150 also includes the guide-tube tools 190 that
fit within the master tubes 120 to help receive the tools and implant.
Each of the guide-tube tools 190 includes a handle region to be manually
grasped. At both ends of the guide-tube tools 190, there are guide tubes
that have a bushing-like structure. The purpose of the guide-tube tools
190 is for mating within the master tube 120 of the surgical guide 110
and, once properly seated in the master tube 120, to receive one or more
of the drill bits 165 used to create the osteotomy. Because creation of
the osteotomy pursuant to the surgical plan calls for a sequence of
several drill bits 165 having different diameters, the guide-tube tools
190 have different diameters to engage the drill bits 165 in a relatively
tight fashion to prevent the drill bit from drilling at the wrong angle.
Thus, for each diameter of a drill bit 165, there is a corresponding
guide-tube tool 190. Further, because the master tubes 120 in the
surgical guide 110 may come in different sizes to receive different sized
implants, the guide-tube tools 190 may have different outer diameters for
mating with the different sized mater tubes 120. As an example, the lower
two guide-tube tools 190 may only be used with a master tube 120 with a
5.1 mm inner diameter.

[0046] The surgical kit 150 further includes tissue punches 202 for
removal of a known size of gingival tissue from beneath the openings in
the surgical guide 110. The surgical kit 150 also includes starter drills
204, such as drill bits for creating a pilot hole and, possibly,
countersinks for creating a certain shape to the opening of the
osteotomy. The surgical kit 150 may include other types of tools such as
implant holders 208 for holding the implants as they are mated with the
correct implant mounts 180 and wrenches/drivers 206 for engaging the
driving element of the implant mount 180. The surgical kit 150 is
preferably made of any material that allows it to be sterilized via an
autoclave.

[0047] FIGS. 9-10 provide a series of illustrations in which the surgical
guide 110 is used to place the actual dental implants 170 within the
patient's mouth in accordance with the pre-established dental surgical
plan that located the virtual implants 70. As mentioned previously, a
surgical guide 110 was created through a technique that allows it to have
a negative impression of the tissue surface within the patient's lower
jaw bone. Accordingly, after it has been developed, the surgical guide
110 can be installed into the patient's mouth such that it fits snugly
over the gingival tissue or teeth or bone. The surgical guide 110 is held
in place in the patient's mouth by use of small, temporary fixations
screws or pins 225 that fit through the openings 128 in the surgical
guide 110. Once it is fixed in place, the surgical guide 110 is used to
conduct surgery in accordance to the dental plan discussed above.

[0048] FIG. 9 illustrates the use of a certain guide-tube tool 190 that
fits within one of the master tubes 120 of the surgical guide 110. The
guide-tube tool 190 then receives a first drill bit 165 (for example, a
pilot drill) that is powered by a driver. Because of the various fluids
and materials that can build up during the surgery within patient's
mouth, a suction tube 230 is often employed.

[0049] FIG. 10 illustrates the placement of one of the dental implants
170, which has been attached to a specifically-sized implant mount 180 in
accordance to the surgical plan. In particular, the implant 170 has been
screwed into the bone by use of a tool that engages the driving element
of the implant mount 180. Because the underlying anti-rotational feature
172 of the implant 110 (the same as anti-rotational feature 72 of the
implant 70 in FIG. 5) is aligned with the notch 187 of the flange 186 of
the implant mount 180, the non-rotational feature 172 is oriented in the
exact location defined by the dental surgical plan by aligning the notch
187 of the implant mount 180 with the notch 124 in the master tube 120. A
tool 240 may be used to detect the alignment of the notch 124 and the
notch 187. As discussed previously, because the implant mount 180 has a
known length, the exact depth of the implant 170 within the osteotomy is
also known, as defined by the dental plan for that patient.

[0050]FIG. 11 illustrates a flow chart 300 for use in creating a surgical
guide in accordance to the present invention. At step 302, a CT scan is
taken of the region in the patient's mouth that will receive the dental
implants. At step 304, a CT scan is taken of the patient's mouth in the
opened position. Next, at step 306, the data from the CT scans at step
302 and 304 is then imported into computer modeling software and used to
develop a 3-D virtual model of the patient's mouth. The data from the CT
scans at step 302 and 304 is then merged, via a shape-matching algorithm
to develop a unitary virtual model. The shape-matching algorithm, as is
commonly known in CAD/CAM and scanning systems, utilizes common features
(e.g., bone, markers, teeth, scanning appliances, etc.) in the two scans
to locate the relative position of one set of data to the other set of
data. With the use of the virtual model created by the CT scans at step
302 and 304, the surgical plan is developed along with the surgical guide
to be used with the surgical plan at step 306.

[0051] Based on the data from the second CT scan of step 304, the
instrumentation suggested for use in accordance with the surgical plan
can be compared against the available dimensions within the patient's
mouth. Thus, at step 308, the dimensions of the instrumentation suggested
for use with each implant in the surgical plan (according to system
parameters) are compared against the available dimensions to ensure that
there will be no spatial problems encountered in the patient's mouth.
Accordingly, at step 310, if spatial problems are encountered, the
surgical plan must be altered to ensure that no spatial problems will be
encountered during the actual surgery in the patient's mouth. As such, at
step 312, for any implant that has encountered a problem, the alterations
related to the implant or the suggested instrumentation can occur.
Examples of such alterations may include (i) changes to the size of the
implant or the implant mount, (ii) changes to the location (e.g., angular
orientation and/or position) of the implant in the bone, (iii) changes to
the surgical guide, and/or (iv) changes to the instrumentation that is to
be used for a certain implant.

[0052] Once the alteration of the surgical plan at step 312 has occurred,
the information from the second CT scan is again used to ensure that the
newly suggested instrumentation (based on the alteration of the surgical
plan) will not cause spatial problems in the patient's mouth (i.e., step
308 is repeated). If no spatial problems are encountered at step 310,
then manufacturing data for the virtual surgical guide can be developed
for use in manufacturing the actual surgical guide, as in step 314. Once
the actual surgical guide is manufactured, it can then be delivered to
the clinician for placement in the patient's mouth (as in step 314)_and
for conducting surgery in accordance with the surgical plan derived from
the virtual model.

[0053] Considering the various alterations that are possible at step 312,
it should be noted that some of those possible alterations inherently
involve a change to the virtual surgical guide 50. For example, changes
to the position and/or orientation of the virtual implant 70 will also
include changes to the openings corresponding to the master tubes 120 in
the virtual surgical guide 50. On the other hand, some alterations may
not require a change to the virtual surgical guide 50. For example, if a
shorter implant or a shorter implant mount is selected as an alteration,
no alterations to the virtual surgical guide 70 may be needed. In a
further possible arrangement, only an alteration to the virtual surgical
guide may be necessary. For example, a spatial problem may be so minor
that simply altering the thickness of the surgical guide may be enough to
alleviate the problem. Or, changing the angle of an opening in the
virtual surgical guide may be enough to alleviate the problem.

[0054] In an alternative embodiment, the present invention contemplates
the use of only a single scan with the mouth in the opened position. In
other words, the single scan gathers enough information about the implant
installation site, while also providing enough information about the
opened-mouth condition that allows for the determination of spatial
limitations. Thus, when considering FIG. 11, step 302 would be
unnecessary and, in step 306, the virtual model would be developed by the
single scan of the opened mouth.

[0055] If a single scan is used, then a need exists for providing a bite
registration between the upper jaw conditions and the lower jaw
conditions. One way to accomplish this task is by the use of a scanning
appliance that has been modified to include material for the bite
registration. The scanning appliance for the patient may include a layer
of barium sulfate of the modeled teeth structures such that the teeth
structures are identified by the CT scan. Next, impression material is
added to the region of the scanning appliance at which the bite
registration for the opposing teeth is expected. The patient would then
close his or her mouth to create the bite registration in the impression
material on the scanning appliance. Once hardened, the impression
material is then provided with a layer of barium sulfate (or other
material that is identifiable by the scan) at a different concentration
level so that the patient's bite registration can be independently
identified in the single CT scan and distinguished from the teeth
structure on the scanning appliance. More information about CT-scanning
and the use of scanning appliances can be found in the product brochure
entitled "Simplant® SurgiGuide Cookbook" from Materialise US Clinical
Services, Inc., Glen Burnie, Md., which is herein incorporated by
reference in its entirety. After the patient undergoes the single scan
with the mouth in the opened position using the scanning device having
the bite registration, a virtual model of the patient's mouth in the
closed position can be created by merging the upper and lower conditions
with a shape-matching algorithm. The surgical plan can be developed, and
the instrumentation to be used in the surgical plan can be checked for
spatial constraints, as described above. As such, the present invention
contemplates the use of a scanning appliance that has been modified to
include a representation of a bite registration.

[0056] It should also be noted that present invention contemplates the use
of virtual modeling to develop a surgical plan that does not require the
use of a surgical guide. In other words, the CT-scans (or CT-scan) are
used by the clinician to develop a virtual model indicating appropriate
locations for the implants based on the conditions in the patient's
mouth. While no surgical guide is developed to dictate the exact angular
position and location of each implant in the patient's mouth, the virtual
model is still used for pre-operative visualization to determine whether
instrumentation will fit into the patient's mouth to place the implants.
If the spatial constraints indicate that instrumentation will not fit,
then changes to the instrumentation or the surgical plan may be needed.

[0057] Similarly, the present invention contemplates the use of virtual
modeling to develop a non-dental implant surgical plan that measures
whether instrumentation will fit within the patient's mouth to accomplish
the non-dental implant surgical plan. Again, the virtual model is used
for pre-operative visualization to determine whether instrumentation will
fit into the patient's mouth when performing the non-dental implant
surgical plan.

[0058] While particular embodiments and applications of the present
invention have been illustrated and described, it is to be understood
that the invention is not limited to the precise construction and
compositions disclosed herein and that various modifications, changes,
and variations may be apparent from the foregoing descriptions without
departing from the spirit and scope of the invention as defined in the
appended claims.